What sort of fish/aquatic creature can survive in the pond behind my house?

There is a fairly large pond behind my house, comparable to a lake. It is about 10 -20 feet deep in the deepest places. There are currently no living creatures other than turtles and snakes. How can I get some fish in here or any type of aquatic creature? I know you can buy those mini shrimp that hatch when you mix them with water, but can you buy them in huge quantities? Are there any types of fish I can purchase online?